chundoong-lab-ta/SamsungDS22/submissions/HW2/g.kwak/mat_mul.cpp

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2022-09-29 18:01:45 +09:00
#include "mat_mul.h"
#include <cstdlib>
#include <cstdio>
#include <pthread.h>
static float *A, *B, *C;
static int M, N, K;
static int num_threads;
static void* mat_mul_thread(void *data) {
// TODO: parallelize & optimize matrix multiplication
int pid = * (int *) data;
int slice = M / num_threads;
int start = pid * slice;
int end = (pid == num_threads - 1) ? M : (pid + 1) * slice;
int j;
int i;
int k;
int kk, kk_min;
int bs = 32;
int NM = (N/8)*8;
float Aik;
for (kk = 0; kk < K; kk += bs) {
for (i = start; i < end; ++i) {
kk_min = (kk+bs <= K) ? kk+bs : K;
for (k = kk; k < kk_min; ++k) {
Aik = A[i * K + k];
for (j = 0; j < NM; j+=8) {
C[i * N + j ] += Aik * B[k * N + j ];
C[i * N + j+1] += Aik * B[k * N + j+1];
C[i * N + j+2] += Aik * B[k * N + j+2];
C[i * N + j+3] += Aik * B[k * N + j+3];
C[i * N + j+4] += Aik * B[k * N + j+4];
C[i * N + j+5] += Aik * B[k * N + j+5];
C[i * N + j+6] += Aik * B[k * N + j+6];
C[i * N + j+7] += Aik * B[k * N + j+7];
}
for (j; j < N; j++) {
C[i * N + j ] += Aik * B[k * N + j ];
}
}
}
//}
}
return NULL;
}
void mat_mul(float *_A, float *_B, float *_C, int _M, int _N, int _K, int _num_threads) {
A = _A, B = _B, C = _C;
M = _M, N = _N, K = _K;
num_threads = _num_threads;
// TODO: create '_num_threads' pthreads
pthread_t * thread;
thread = (pthread_t *) malloc(sizeof(pthread_t) * num_threads);
for (int i = 0; i < num_threads; i++) {
int * pid = (int *) malloc(sizeof(int));
*pid = i;
pthread_create(&thread[i], NULL, mat_mul_thread, pid);
}
for (int i = 0; i < num_threads; i++) {
pthread_join(thread[i], NULL);
}
}